Method and device for obtaining motion vector of video image

ABSTRACT

A video processing method includes performing or skipping following processing based on whether a size of a coding unit is not smaller or is smaller than 8×8. The processing includes dividing the coding unit into sub-blocks each having a fixed size of 8×8, scanning a left neighboring block and determining a reference motion vector of the coding unit, determining a related reference block of a sub-block in the co-located reference image according to the reference motion vector, determining a scaling factor of a motion vector of the related reference block, scaling the motion vector of the related reference block using the scaling factor, determining motion information of the sub-block according to the scaled motion vector, and performing prediction for the coding unit according to the motion information.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of International Application No.PCT/CN2018/107436, filed Sep. 25, 2018, which claims priority toInternational Application No. PCT/CN2018/103693, filed Aug. 31, 2018,International Application No. PCT/CN2018/095710, filed Jul. 13, 2018,and International Application No. PCT/CN2018/081652, filed Apr. 2, 2018,the entire contents of all of which are incorporated herein byreference.

The content disclosed in this disclosure contains material which issubject to copyright protection. The copyright is owned by the copyrightowner. The copyright owner has no objection to the facsimilereproduction by anyone of the patent document or the patent disclosureas it appears in the official records and archives of the Patent andTrademark Office.

TECHNICAL FIELD

The present disclosure relates to the field of video encoding anddecoding, and in particular to a method and device for obtaining motionvectors of video images.

BACKGROUND

At present, the main video coding standards adopt block-based motioncompensation technology in inter prediction. The main principle is tofind the most similar block in an encoded image for a current imageblock. This process is called motion compensation. For example, an imageis first divided into coding tree units (CTUs) of equal size, such asthe size of 64×64 or 128×128. Each CTU can be further divided intosquare or rectangular coding units (CUs). For each CU, the most similarblock is searched in a reference frame (generally a re-composite framenear a current frame in the time domain) as a prediction block of thecurrent CU. A relative displacement between the current block (that is,the current CU) and the similar block (that is, the prediction block ofthe current CU) is referred to as a motion vector (MV). The process offinding the most similar block in the reference frame as the predictionblock of the current block is motion compensation.

In the current technology, a motion vector candidate list of the currentCU is usually constructed based on the motion vectors of encodedneighboring blocks of the current CU, which is also known as a Mergecandidate list. An optimal motion vector candidate is selected from theMerge candidate list as the motion vector of the current CU and aprediction block of the current CU is determined according to the motionvector of the current CU.

Advanced/alternative temporal motion vector prediction (ATMVP) is amotion vector prediction mechanism. The basic principle of ATMVPtechnology is to perform motion compensation by obtaining motioninformation of multiple sub-blocks in the current CU. ATMVP technologyintroduces motion information of multiple sub-blocks in the current CUas candidates in constructing a candidate list (such as a Mergecandidate list or an advanced motion vector prediction (AMVP) candidatelist). The ATMVP technology includes two steps. The first step is todetermine a time-domain vector by scanning the current CU candidatelist, and the second step is to divide the current CU into N×N (bydefault, N is 4) sub-blocks (sub-CU), determine a corresponding block ofeach sub-block in the reference frame according to the obtainedtime-domain vector, and determine the motion vector of each sub-blockaccording to the motion vector of the corresponding block of eachsub-block in the reference frame.

In the first step of the current ATMVP technology, the process ofdetermining a time-domain vector by scanning the candidate list of thecurrent CU can be improved.

SUMMARY

In accordance with the disclosure, there is provided a video processingmethod including, in response to a size of a coding unit being notsmaller than 8×8, performing following processing, and, in response tothe size of the coding unit being smaller than 8×8, skipping theprocessing. The processing includes dividing the coding unit intoseveral sub-blocks each having a fixed size of 8×8, scanning a leftneighboring block of the coding unit and, in response to a referenceframe pointed to by a motion vector of the left neighboring block beingsame as a co-located reference image of the coding unit, determining themotion vector of the left neighboring block as a reference motion vectorof the coding unit, and in response to the reference frame pointed to bythe motion vector of the left neighboring block being different from theco-located reference image of the coding unit, determining a defaultvalue (0, 0) as the reference motion vector of the coding unit. Theprocessing further includes determining a related reference block of oneof the sub-blocks of the coding unit in the co-located reference imageof the coding unit according to the reference motion vector of thecoding unit. The processing also includes, in response to a motionvector of the related reference block of the one of the sub-blockspointing to a short-term reference image, determining a scaling factorof the motion vector of the related reference block of the one of thesub-blocks according to a temporal distance between a reference imagepointed to by the motion vector of the related reference block of theone of the sub-blocks and the co-located reference image of the codingunit and a temporal distance between the co-located reference image ofthe coding unit and an image containing the coding unit, scaling themotion vector of the related reference block of the one of thesub-blocks using the scaling factor, and determining motion informationof the one of the sub-blocks according to the motion vector after beingscaled. The processing also includes, in response to the motion vectorof the related reference block of the one of the sub-blocks pointing toa long-term reference image, setting the scaling factor of the motionvector of the related reference block of the one of the sub-blocks to 1,scaling the motion vector of the related reference block of the one ofthe sub-blocks using the scaling factor, and determining the motioninformation of the one of the sub-blocks according to the motion vectorafter being scaled. The processing also includes performing predictionfor the coding unit according to the motion information of the one ofthe sub-blocks.

Also in accordance with the disclosure, there is provided a videoprocessing device including a memory storing computer executableinstructions and a processor configured to execute the instructions to,in response to a size of a coding unit being not smaller than 8×8,perform following processing, and, in response to the size of the codingunit being smaller than 8×8, skip the processing. The processingincludes dividing the coding unit into several sub-blocks each having afixed size of 8×8, scanning a left neighboring block of the coding unitand, in response to a reference frame pointed to by a motion vector ofthe left neighboring block being same as a co-located reference image ofthe coding unit, determining the motion vector of the left neighboringblock as a reference motion vector of the coding unit, and in responseto the reference frame pointed to by the motion vector of the leftneighboring block being different from the co-located reference image ofthe coding unit, determining a default value (0, 0) as the referencemotion vector of the coding unit. The processing further includesdetermining a related reference block of one of the sub-blocks of thecoding unit in the co-located reference image of the coding unitaccording to the reference motion vector of the coding unit. Theprocessing also includes, in response to a motion vector of the relatedreference block of the one of the sub-blocks pointing to a short-termreference image, determining a scaling factor of the motion vector ofthe related reference block of the one of the sub-blocks according to atemporal distance between a reference image pointed to by the motionvector of the related reference block of the one of the sub-blocks andthe co-located reference image of the coding unit and a temporaldistance between the co-located reference image of the coding unit andan image containing the coding unit, scaling the motion vector of therelated reference block of the one of the sub-blocks using the scalingfactor, and determining motion information of the one of the sub-blocksaccording to the motion vector after being scaled. The processing alsoincludes, in response to the motion vector of the related referenceblock of the one of the sub-blocks pointing to a long-term referenceimage, setting the scaling factor of the motion vector of the relatedreference block of the one of the sub-blocks to 1, scaling the motionvector of the related reference block of the one of the sub-blocks usingthe scaling factor, and determining the motion information of the one ofthe sub-blocks according to the motion vector after being scaled. Theprocessing also includes performing prediction for the coding unitaccording to the motion information of the one of the sub-blocks.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic flowchart of a method for obtaining a motionvector of a video image according to an embodiment of the disclosure.

FIG. 2 is a schematic diagram showing obtaining a candidate motionvector of a current block through a neighboring block of a current imageblock.

FIG. 3 is a schematic diagram showing scaling a candidate motion vector.

FIG. 4 is another schematic flowchart of a method for obtaining a motionvector of a video image according to an embodiment of the disclosure.

FIG. 5 is a schematic block diagram of a device for processing videoimages according to an embodiment of the disclosure.

FIG. 6 is a schematic block diagram of a device for processing videoimages according to another embodiment of the disclosure.

FIG. 7 is a schematic flowchart of a method for processing video imagesaccording to an embodiment of the disclosure.

FIG. 8 is a schematic flowchart of a method for processing video imagesaccording to another embodiment of the disclosure.

FIG. 9 is a schematic block diagram of a device for processing videoimages according to another embodiment of the disclosure.

FIG. 10 is a schematic block diagram of a device for processing videoimages according to another embodiment of the disclosure.

FIG. 11 is a schematic block diagram of a device for processing videoimages according to another embodiment of the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Motion vectors are explained first to facilitate understanding of thefollowing description. A motion vector of an image block may includeinformation of an image pointed to by the motion vector and adisplacement. The motion vector of an image block means one image blockin the image pointed to by the motion vector that has the displacementrelative to the image block. For an encoded/decoded image block, themotion vector means a reference image of the encoded/decoded imageblock, and a displacement of a reference block of the encoded/decodedimage block relative to the encoded/decoded image block. The referenceblock of an image block mentioned in this disclosure refers to an imageblock used to calculate residuals of the image block.

FIG. 1 is a schematic flowchart of a method for obtaining a motionvector of a video image according to an embodiment of the presentdisclosure.

At S110, M candidate motion vectors for adding to a motion vectorcandidate list of a current image block are obtained. M is a positiveinteger.

The current image block is an image block to be encoded (or decoded). Animage frame where the current image block is located is referred to as acurrent frame.

For example, the current image block is a coding unit (CU).

For example, the motion vector candidate list of the current image blockmay be a Merge candidate list or an AMVP candidate list.

The motion vector candidate list may also have another name.

The M candidate motion vectors may be determined according to motionvectors of M neighboring blocks of the current image block in thecurrent frame. The neighboring block may be an image block adjacent orhaving a certain distance to the current image block in the currentframe. The M neighboring blocks are image blocks in the current framethat have been encoded (or decoded).

For example, as shown in FIG. 2, the M neighboring blocks of the currentimage block are the image blocks at four locations A₁ (left)→B₁ (top)→B₀(upper right)→A₀ (lower left) around the current image block. The motionvectors of the image blocks at these four locations are used as the M(that is, M equals 4) candidate motion vectors of the current imageblock.

In some embodiments, after the process of S110 is completed, the Mcandidate motion vectors are added to the motion vector candidate list.At S120, the motion vector candidate list may be directly scanned.

At S120, N candidate motion vectors among the M candidate motion vectorsare scanned sequentially, and a reference motion vector is determinedaccording to a scan result, where N is an integer smaller than M.

Determining the reference motion vector according to the scan result ofthe N candidate motion vectors may include checking the N candidatemotion vectors sequentially based on a preset condition and determiningthe reference motion vector according to the checking result.

For example, the preset condition is that a reference frame pointed toby the candidate motion vector is the same as a reference image of thecurrent image block.

The reference image of the current image block is a reference image witha shortest temporal distance to the image where the current image blockis located, or the reference image of the current image block is areference image preset at the encoding and decoding ends, or thereference image of the current image block is a reference imagespecified in a video parameter set, a sequence header, a sequenceparameter set, an image header, an image parameter set, or a sliceheader.

For example, the reference image of the current image block is acollocated frame of the current image block, and the collocated frame isa frame set in a slice-level information header for obtaining motioninformation for prediction. In some application scenarios, thecollocated frame is also referred to as a collocated picture.

According to the evolution of future technology, the preset conditionmay be given other different definitions, and the corresponding solutionalso falls within the scope of the present disclosure.

The process of determining the reference motion vector according to thescan result of N candidate motion vectors is described in detail below.

At S120, only N motion vectors among the M candidate motion vectors thatare obtained in the process of S110 are scanned, which can reduce thenumber of scans.

In some embodiments, at S120, the first N candidate motion vectors amongthe M candidate motion vectors may be sequentially scanned.

In some embodiments, at S120, the last N candidate motion vectors amongthe M candidate motion vectors may be sequentially scanned, or, themiddle N candidate motion vectors among the M candidate motion vectorsmay be sequentially scanned, which is not limited in the disclosure.

For one example, at S120, some of the candidate motion vectors among theM candidate motion vectors are sequentially scanned.

For another example, at S120, some of the candidate motion vectors amongthe candidate motion vectors that are currently added to the motionvector candidate list are sequentially scanned.

At S130, candidate motion vectors to be added to the motion vectorcandidate list are continued to be determined according to the referencemotion vector, the current image block, and the reference image of thecurrent image block. That is, additional candidate motion vectors to beadded to the motion vector candidate list can be determined according tothe reference motion vector, the current image block, and the referenceimage of the current image block.

After the process of S130 is completed, the construction of the motionvector candidate list of the current image block is completed. Themotion vector candidate list of the current image block includes the Mcandidate motion vectors determined at S110 and the candidate motionvectors determined at S130.

As shown in FIG. 1, the method further includes determining a motionvector of the current image block according to the motion vectorcandidate list obtained at S130 (S140).

The solution provided in this disclosure can be applied to the ATMVPtechnology. For example, the first step in the ATMVP technology can berealized through the process of S120.

In the first step of the ATMVP technology, a time-domain vector of thecurrent image block is obtained by scanning all candidate motion vectorsthat are currently added in the motion vector candidate list. Forexample, the motion vector candidate list is usually filled with 4candidate motion vectors, hence all the 4 candidate motion vectors mayneed to be scanned to obtain the time-domain vector of the current imageblock.

In some embodiments, in the process of obtaining the reference motionvector of the current image block, only N (N is smaller than M)candidate motion vectors among the M candidate motion vectors that havebeen obtained are sequentially scanned. Comparing with the existingtechnology, the number of scans of the candidate motion vectors in theprocess of obtaining the reference motion vector of the current imageblock can be reduced. Applying the solution provided by the presentdisclosure to the first step of the ATMVP technology can simplify theredundant operations.

An official test sequence of the latest reference software VTM-2.0 ofversatile video coding is selected as the test sequence. The testconfiguration is RA configuration and LDB configuration. The solutionprovided by this disclosure is tested and the test result shows that theperformance gain of ATMVP technology can still be maintained after thenumber of scans is reduced.

Therefore, the solution provided in this disclosure can reduce thecomplexity of the ATMVP technology while maintaining the performancegain of the ATMVP technology.

The method for constructing a motion vector candidate list provided bythis disclosure may be applied to the encoding end or the decoding end.In other words, the execution entity of the method provided by thepresent disclosure may be the encoding end or the decoding end.

In some embodiments, at the encoding end, after the motion vectorcandidate list is obtained through the method according to theembodiments of the present disclosure, the current image block may beencoded by the following processes.

1) Select an optimal motion vector (denoted as MV1) from the motionvector candidate list, use the selected MV1 as the motion vector of thecurrent image block, and obtain an index of the MV1 in the motion vectorcandidate list.

2) Determine a predicted image block of the current image block from thereference image (i.e., reference frame) according to the motion vectorMV1 of the current image block. That is, a position of the predictedimage block of the current image block in the reference frame isdetermined.

3) Obtain a residual between the current image block and the predictedimage block.

4) Send the index of the motion vector MV1 of the current image block inthe motion vector candidate list and the obtained residual to thedecoding end.

In some embodiments, at the decoding end, the current image block can bedecoded by the following processes.

1) Receive the residual and the index of the motion vector of thecurrent image block in the motion vector candidate list from theencoding end.

2) Obtain a motion vector candidate list through the method according tothe embodiments of the present disclosure, where the motion vectorcandidate list obtained by the decoding end is consistent with themotion vector candidate list obtained by the encoding end.

3) Obtain the motion vector MV1 of the current image block from themotion vector candidate list according to the index.

4) Obtain the predicted image block of the current image block, and thencombine the residuals to obtain the current image block by decodingaccording to the motion vector MV1.

In some embodiments, at S110, according to the motion vectors of the 4neighboring blocks of the current image block in the current frame, the4 candidate motion vectors to be added to the motion vector candidatelist of the current image block are determined. That is, M is equal to4. At S120, N candidate motion vectors among the 4 candidate motionvectors are scanned, and N is smaller than 4.

For example, N is equal to 1. At S120, only the first motion vectorcandidate in the motion vector candidate list is scanned.

For another example, N is equal to 2 or 3.

The method for determining the reference motion vector of the currentimage block according to the scan result of the N candidate motionvectors at S120 is described below.

At S120, it is determined one by one whether the N candidate motionvectors among the M candidate motion vectors satisfy the presetcondition, and the reference motion vector is determined according tothe determination result. In some embodiments, the preset condition isthat the reference frame pointed to by the candidate motion vector isthe same as the reference image of the current image block.

In some embodiments, at S120, the N candidate motion vectors aresequentially scanned. When a first candidate motion vector that meetsthe preset condition is determined, that is, when a first candidatemotion vector that points to a reference frame same as the collocatedframe of the current frame is determined, the scanning is stopped, andthe reference motion vector is determined according to the first scannedcandidate motion vector that meets the preset condition.

When the first candidate motion vector meeting the preset condition isscanned, the number of scans may be equal to N, or smaller than N.

For example, when the candidate motion vector of the first scansatisfies the preset condition, the scanning is stopped, and thiscandidate motion vector is used as the reference motion vector of thecurrent image block.

In some embodiments, at S120, when no candidate motion vector meetingthe preset condition is found among the N candidate motion vectors, thatis, when the reference frames pointed to by the N candidate motionvectors are all different from the collocated frame of the current imageblock, a default value is used as the value of the reference motionvector.

For example, the default value is (0, 0), that is, the reference motionvector is (0, 0).

According to actual scenarios, the default value may have otherdefinitions.

In some embodiments, at S120, when no candidate motion vector meetingthe preset condition is found among the N candidate motion vectors, thatis, when the reference frames pointed to by the N candidate motionvectors are all different from the collocated frame of the current imageblock, a specific candidate motion vector in the motion vector candidatelist is scaled, and the reference motion vector is determined accordingto the scaled specific candidate motion vector.

The specific candidate motion vector may be the first motion vector orthe last motion vector obtained according to the scanning order amongthe N candidate motion vectors.

The specific candidate motion vector may also be a motion vectorobtained in other scanning order among the N candidate motion vectors.

When the preset condition is that the reference frame pointed to by thecandidate motion vector is the same as the reference frame of thecurrent image block, the specific candidate motion vector in the motionvector candidate list is scaled. Determining the reference motion vectoraccording to the scaled specific candidate motion vector includesscaling the specific candidate motion vector in the motion vectorcandidate list, so that the reference frame pointed to by the scaledspecific candidate motion vector is the same as the reference image ofthe current image block, and using the scaled specific candidate motionvector as the reference motion vector.

As shown in FIG. 3, curr_pic represents the image where the currentimage block is located, col_pic represents the collocated frame of thecurrent image block, and neigh_ref_pic represents the reference framepointed to by the specific candidate motion vector. In some embodiments,a scaling factor of the specific motion vector is determined accordingto a temporal distance between the reference image neigh_ref_pic pointedto by the specific candidate motion vector and the image curr_pic wherethe image block corresponding to the specific motion vector is located,and a temporal distance between the reference image col_pic of thecurrent image block and the image curr_pic where the current image blockis located.

The difference in the motion intensity between one image frame andanother image frame is poor. In the scenario with intense motion betweenthe current frame and its collocated frame, if the motion vector (0, 0)is used as the basis for locating the corresponding block of the currentblock, the movement between frames is not considered and the absolutecoordinates of the current block in the collocated frame are directlyassumed to have not changed, and in fact there is a high probabilitythat the coordinates of the current block in the collocated frame aredifferent from the coordinates of the current block in the currentframe. Therefore, a large deviation may occur.

In the embodiments of the present disclosure, when no candidate motionvector whose reference frame is the same as the collocated frame of thecurrent frame is found among the N candidate motion vectors, onecandidate motion vector among the N candidate motion vectors is scaledto make the reference frame the same as the collocated frame of thecurrent frame, and then the scaled candidate motion vector is used asthe motion vector of the current image block. In this way, the accuracyof the motion vector of the current image block can be improved.

In some embodiments, when N is an integer smaller than M and greaterthan 1, the specific candidate motion vector in the embodiments may be acandidate motion vector that has a shortest temporal distance betweenthe reference frame and the collocated frame of the current image blockamong the N candidate motion vectors.

Selecting a candidate motion vector with the shortest distance betweenthe reference frame and the collocated frame of the current frame amongthe N candidate motion vectors to scale can reduce the time for scalingprocessing, thereby improving the efficiency of obtaining the motionvector of the current image block.

In some embodiments, when N is an integer smaller than M and greaterthan 1, the specific candidate motion vector in the embodiments may alsobe any candidate motion vector among the N candidate motion vectors.

When N is equal to 1, the specific candidate motion vector in theembodiments is the scanned candidate motion vector.

In some embodiments, N is equal to 1. At S120, a reference motion vectorof the current image block is obtained by scanning one candidate motionvector in the motion vector candidate list. When the scanned candidatemotion vector points to a reference frame that is different from thecollocated frame of the current frame where the current image block islocated, the candidate motion vector is scaled so that the referenceframe of the scaled candidate motion vector is the same as thecollocated frame of the current frame, and the scaled candidate motionvector is used as the reference motion vector of the current imageblock. When the reference frame of the scanned candidate motion vectoris the same as the collocated frame of the current frame, the candidatemotion vector is used as the motion vector of the current image block.

In some embodiments, the motion vector of the current image block isobtained by scanning one candidate motion vector in the candidate motionvector list, the number of times of scanning the candidate motion vectorin the process of obtaining the motion vector of the current image blockis effectively reduced. When the reference frame of the scannedcandidate motion vector is different from the collocated frame of thecurrent frame, the candidate motion vector is scaled to make thereference frame the same as the collocated frame of the current frame,and then the scaled candidate motion vector is used as the motion vectorof the current image block. In this way, the accuracy of the motionvector of the current image block can be improved. Therefore, comparedwith the existing technology, the solution provided by the embodimentsof the present disclosure not only can simplify the process ofdetermining the motion vector of the current image block, but also canimprove the accuracy of the motion vector of the current image block.

When the preset condition changes, the process of scaling the specificcandidate motion vector in the motion vector candidate list also needsto be changed accordingly, that is, to ensure that the scaled specificcandidate motion vector satisfies the preset condition.

The process of determining candidate motion vectors to be added to themotion vector candidate list according to the reference motion vector,the current image block, and the reference image of the current imageblock at S130 is described below.

In some embodiments, determining candidate motion vectors to be added tothe motion vector candidate list according to the reference motionvector, the current image block, and the reference image of the currentimage block includes dividing the current image block into multiplesub-images blocks, determining a related block of the sub-block in thereference image of the current image block according to the referencemotion vector, and determining the candidate motion vector to be addedto the motion vector candidate list according to the motion vector ofthe related block.

The related block may be referred to as a collocated block orcorresponding block.

For example, the current image block is a CU, and the sub-block obtainedafter dividing the CU may be referred to as a sub-CU.

In some embodiments, the size of the sub-block and/or the size of therelated block of the sub-block is fixed to be greater than or equal to64 pixels.

In some embodiments, the size of the sub-block and/or the size of therelated block of the sub-block are both fixed at 8×8 pixels.

In the ATMVP technology, the size of the sub-block can be adaptively setat the frame level. The size of the sub-block is 4×4 by default. When acertain condition is met, the size of the sub-block is set to 8×8. Forexample, at the encoding end, when the current image block is encoded,the average block size of each sub-block in the CU is calculated whenthe last encoded image block in the same time-domain layer is encoded inATMVP mode. When the average block size is greater than a threshold, thesize of the sub-block of the current image block is set to 8×8,otherwise the default value of 4×4 is used. At present, in a newgeneration of the versatile video coding standard (VVC), the motionvector is stored with a size of 8×8. When the size of the sub-block isset to 4×4, the size of the motion vector of the sub-block (also 4×4)does not meet the storage granularity of the motion vector in thecurrent standard. In addition, in the ATMVP technology, when the currentimage block is encoded, information about the size of the sub-block ofthe previous encoded image block in the same time-domain layer needs tobe stored.

In the embodiments of the present disclosure, the size of the sub-blockof the current image block can be set to 8×8 to adapt to the storagegranularity of the motion vector specified in the video standard VVC onthe one hand, and on the other hand, there is no need to store theinformation of the size of the sub-block of the last encoded imageblock, therefore, the storage space is saved.

On the premise that the size of the sub-block and/or the related blockof the sub-block is fixed to be equal to 64 pixels, the size of thesub-block and/or the related block of the sub-block may also be otherdimensions, for example, the size of the sub-block and/or the size ofthe related block of the sub-block is A×B, where A≤64, B≤64, and A and Bare both multiples of 4. For example, the size of the sub-block and/orthe size of the related block of the sub-block is 4×16 pixels, or 16×4pixels.

In some embodiments, according to the reference motion vector, thecurrent image block, and the reference image of the current image block,determining the candidate motion vector to be added to the motion vectorcandidate list includes determining the related block of the currentimage block in the reference image of the current image block accordingto the reference motion vector, and determining the candidate motionvector to be added to the motion vector candidate list according to themotion vector of the related block.

In the encoding/decoding technology, the encoded/decoded image isgenerally used as the reference image of the current image to beencoded/decoded. In some embodiments, a reference image may also beconstructed to improve the similarity between the reference image andthe current image to be encoded/decoded.

For example, there is a specific type of encoding/decoding scene in thevideo content, in which the background basically does not change andonly the foreground in the video changes or moves. For example, videosurveillance belongs to this type of scene. In video surveillancescenes, the surveillance camera is usually fixed or only moves slowly,and it can be considered that the background basically does not change.In contrast, objects such as people or cars photographed by the videosurveillance cameras often move or change, and it can be considered thatthe foreground changes frequently. In such scenes, a specific referenceimage can be constructed, and the specific reference image contains onlyhigh-quality background information. The specific reference image mayinclude multiple image blocks, and any one image block is taken from adecoded image. Different image blocks in the specific reference imagemay be taken from different decoded images. When inter prediction isbeing performed, the specific reference image can be referred to for thebackground part of the current image to be encoded/decoded, therebyreducing residual information of inter prediction and improvingencoding/decoding efficiency.

The above is a specific example for a specific reference image. In someembodiments, the specific reference image has at least one of thefollowing properties: composite frame, long-term reference image, orimage not for outputting. The image not for outputting refers to animage that is not output for displaying. Generally, the image not foroutputting exists as a reference image to other images. For example, thespecific reference image may be a composite long-term reference image,or may be a composite frame that is not output, or may be a long-termreference image that is not output, and so on. In some embodiments, thecomposite frame is also referred to as a composite reference frame.

In some embodiments, the non-specific reference image may be a referenceimage that does not have at least one of the following properties:composite frame, long-term reference image, or image not for outputting.For example, the non-specific reference image may include a referenceimage other than a composite frame, or include a reference image otherthan a long-term reference image, or include a reference image otherthan an image not for outputting, or include a reference image otherthan a composite long-term reference image, or include a reference imageother than a composite frame that is not output, or include a referenceimage other than a long-term reference image that is not output, and soon.

In some embodiments, when the image in the video can be used as areference image, the image can be a long-term reference image or ashort-term reference image. The short-term reference image is a conceptcorresponding to the long-term reference image and the short-termreference image exists in the reference image buffer for a period oftime. After the operation of moving a decoded reference image after theshort-term reference image in and out of the reference image buffer isperformed for a number of times, the short-term reference image isremoved from the reference image buffer. The reference image buffer mayalso be referred to as a reference image list buffer, a reference imagelist, a reference frame list buffer, or a reference frame list, etc.,which are all referred to as a reference image buffer in thisdisclosure.

The long-term reference image (or part of the data in the long-termreference image) can always exist in the reference image buffer, and thelong-term reference image (or part of the data in the long-termreference image) is not affected by the decoded reference image movingin and out of the reference image buffer. The long-term reference image(or part of the data in the long-term reference image) is only removedfrom the reference image buffer when the decoding end sends an updateinstruction.

The short-term reference image and the long-term reference image may becalled differently in different standards. For example, in standardssuch as H.264/advanced video coding (AVC) or H.265/HEVC, the short-termreference image is called a short-term reference frame, and thelong-term reference image is called a long-term reference frame. Foranother example, in standards such as audio video coding standards (AVS)1-P2, AVS2-P2, and Institute of Electrical and Electronics Engineers(IEEE) 1857.9-P4, the long-term reference image is called a backgroundpicture. As another example, in standards such as VP8 and VP9, thelong-term reference image is called a golden frame.

The specific terminology used in the embodiments of the presentdisclosure does not mean that it must be applied to a specific scene.For example, referring to a long-term reference image as a long-termreference frame does not mean that the technologies corresponding to thestandards of H.264/AVC or H.265/HEVC must be applied.

The long-term reference image described above may be obtained byconstructing image blocks extracted from multiple decoded images, orupdating existing reference frames (for example, pre-stored referenceframes) using multiple decoded images. The composite specific referenceimage may also be a short-term reference image. Or, the long-termreference image may not be the composite reference image.

In the above embodiments, the specific reference image may include along-term reference image, and the non-specific reference image mayinclude a short-term reference image.

In some embodiments, the type of the reference frame can be identifiedby a special field in the stream structure.

In some embodiments, when the reference image is determined to be along-term reference image, the reference image is determined to be aspecific reference image. When the reference image is determined to be aframe that is not output, the reference image is determined to be aspecific reference image. When the reference image is determined to be acomposite frame, the reference image is determined to be a specificreference image. When the reference image is determined to be a framethat is not output and the reference image is further determined to be acomposite frame, the reference image is determined to be a specificreference image.

In some embodiments, various types of reference images may havecorresponding identifiers. At this time, for the decoding end, it may bedetermined whether the reference image is a specific reference imageaccording to the identifier of the reference image.

In some embodiments, when it is determined that the reference image hasthe identifier of the long-term reference image, the reference image isdetermined to be a specific reference image.

In some embodiments, when it is determined that the reference image hasan identifier that is not output, it is determined that the referenceimage is a specific reference image.

In some embodiments, when it is determined that the reference image hasan identifier of the composite frame, the reference image is determinedto be a specific reference image.

In some embodiments, when it is determined that the reference image hasat least two of the following three identifiers: the identifier of thelong-term reference image, the identifier that is not output, theidentifier of the constructed frame or the composite reference frame,the reference image is determined to be a specific reference image. Forexample, when it is determined that the reference image has anidentifier that is not output, and it is determined that the referenceimage has an identifier of the composite frame, the reference image isdetermined to be a specific reference image.

In some embodiments, the image may have an identifier indicating whetherit is a frame to be output. When an image is indicated to be not output,the frame is indicated to be a reference image. Further, it isdetermined whether the frame has an identifier of the composite frame.When the frame has the identifier of the composite frame, the referenceimage is determined to be a specific reference image. If an image isindicated to be output, the frame is directly determined to not be aspecific reference image without determining whether it is a compositeframe. Or, if an image is indicated to be not output, but has anidentifier indicating it is not a composite frame, the frame can bedetermined to not be a specific reference image.

In some embodiments, the reference image can be determined to be aspecific reference image when it is determined that the reference imagemeets one of the following conditions by analyzing parameters from apicture header, a picture parameter set, or a slice header: thereference image is a long-term reference image, the reference image is acomposite reference image, and the reference image is an image not foroutputting, or the reference image is an image not for outputting and isfurther determined to be a composite reference image.

In some embodiments, the process of determining the motion vector of thecurrent image block involves using a motion vector of a certain imageblock on another image to determine the motion vector of the imageblock. For convenience of description, the image block is referred to asa first image block, and the certain image block on another image to beused is referred to as a time-domain reference block or a related blockof the first image block. The first image block and the time-domainreference block (or the related block) of the first image block arelocated on different images. Then, in the process of determining themotion vector of the first image block using the motion vector of thetime-domain reference block (or the related block), the motion vector ofthe time-domain reference block (or the related block) needs to bescaled. For convenience of description, the term “related block” is usedin the disclosure.

For example, when the ATMVP technology is applied in constructing theAMVP candidate list, and when the motion vector of the related block ofthe current image block is determined according to the ATMVP technology,the motion vector of the related block needs to be scaled, and thenmotion vector of the current image block is determined according to thescaled motion vector. Generally speaking, a scaling factor of the motionvector of the related block is determined based on a temporal distancebetween the reference image pointed to by the motion vector of relatedblock and the image where the related block is located, and a temporaldistance between the reference image of the current image block and theimage where the current image block is located.

In one example, the motion vector of the related block is referred to asMV 2, and the index value of the reference frame of the reference imagepointed to by the motion vector MV 2 is x. The index value x of thereference frame is the difference between the sequence number of thereference image pointed to by MV 2 (for example, POC) and the sequencenumber of the image where the related block is located. The index valueof the reference frame of the reference image of the first image blockis y. The index value y of the reference frame is the difference betweenthe sequence number of the reference image of the first image block andthe sequence number of the image where the first image block is located.Then, the scaling factor of the motion vector MV 2 is y/x. In someembodiments, the product of the motion vector MV 2 and y/x may be usedas the motion vector of the first image block.

However, when the motion vector MV 2 of the related block points to aspecific reference image, or when the reference image of the first imageblock is a specific reference image, because the definition of thetemporal distance between the specific reference image and the imagewhere the first image block is located is not clear, it may bemeaningless to scale the motion vector MV 2 of the related block.

In some embodiments, when the motion vector of the current image blockis determined according to the motion vector of the related block, andwhen the motion vector of the related block points to a specificreference image, or the reference image of the current image block is aspecific reference image, the motion vector of the current image blockis determined according to a processed motion vector of the relatedblock. The processed motion vector of the related block is the same asthe motion vector of the related block before processing.

For example, the processed motion vector of the related block includes amotion vector obtained by scaling the motion vector of the related blockaccording to a scaling factor of 1, or a motion vector of the relatedblock skipping the scaling process.

In some embodiments, when the motion vector of the current image blockis determined according to the motion vector of the related block, andwhen the motion vector of the related block points to a specificreference image, or when the reference image of the current image blockis a specific reference image, the motion vector of the current imageblock is determined without referencing to the motion vector of therelated block.

In some embodiments, at S120, if no candidate motion vector that meets apreset condition is found among the N candidate motion vectors, aspecific candidate motion vector in the motion vector candidate list isscaled, and then a reference motion vector is determined according tothe scaled specific candidate motion vector. In some embodiments, themethod further includes, when the specific candidate motion vectorpoints to the specific reference image, or when the reference image ofthe current image block is the specific reference image, determining thecandidate motion vector to be added to the motion vector candidate listaccording to the processed specific candidate motion vector. Theprocessed specific candidate motion vector is the same as the specificcandidate motion vector before processing.

The processed motion vector of the related block includes a motionvector obtained by scaling the motion vector of the related blockaccording to a scaling factor of 1, or a motion vector of the relatedblock skipping the scaling process.

In some embodiments, at S120, if no candidate motion vector that meetsthe preset condition is found among the N candidate motion vectors, aspecific candidate motion vector in the motion vector candidate list isscaled, and then a reference motion vector is determined according tothe scaled specific candidate motion vector. In some embodiments, themethod further includes, when the specific candidate motion vectorpoints to the specific reference image, or when the reference image ofthe current image block is the specific reference image, determining thecandidate motion vector to be added to the motion vector candidate listwithout referencing to the specific candidate motion vector.

In the embodiments of the present disclosure, in the process ofobtaining the reference motion vector of the current image block, only N(N is smaller than M) candidate motion vectors among the M candidatemotion vectors that have been obtained are sequentially scanned.Comparing with the existing technology, the number of scans of thecandidate motion vectors in the process of obtaining the referencemotion vector of the current image block can be reduced. Applying thesolution provided by the present disclosure to the first step of theATMVP technology can simplify the redundant operations.

When no candidate motion vector whose reference frame is the same as thecollocated frame of the current frame is found among the N candidatemotion vectors, one candidate motion vector among the N candidate motionvectors is scaled to make the reference frame the same as the collocatedframe of the current frame, and then the scaled candidate motion vectoris used as the motion vector of the current image block. In this way,the accuracy of the motion vector of the current image block can beimproved.

Dividing the current image block into multiple sub-blocks with a size of8×8 can adapt to the storage granularity of the motion vector specifiedin the video standard VVC on the one hand, and on the other hand, thereis no need to store the information of the size of the sub-block of thelast encoded image block, therefore, the storage space is saved.

FIG. 4 shows a method for obtaining a motion vector of a video imageaccording to an embodiment of the present disclosure.

At S410, M candidate motion vectors for adding to a motion vectorcandidate list of a current image block are obtained.

The process of S410 corresponds to the process of S110 described above.For the specific description, reference can be made to the descriptionabove, which is not repeated here.

At S420, at least some of the candidate motion vectors among the Mcandidate motion vectors are scanned sequentially, and a referencemotion vector of the current image block is determined according to thescan result.

In some embodiments, some of the candidate motion vectors among the Mcandidate motion vectors are sequentially scanned, and the referencemotion vector of the current image block is determined according to thescan result. The process of S420 may correspond to the process of S120described above. Specific description thereof is omitted.

In some other embodiments, all candidate motion vectors among the Mcandidate motion vectors are sequentially scanned, and the referencemotion vector of the current image block is determined according to thescan result.

For a specific manner of determining the reference motion vector of thecurrent image block according to the scan result at S420, reference maybe made to the related description in the foregoing embodiments, anddetails are not repeated here.

At S430, the current image block is divided into multiple sub-blocks,and a size of the sub-block is fixed to be greater than or equal to 64pixels.

For example, the current image block is referred to as a CU, and thesub-block obtained after dividing the CU may be referred to as a sub-CU.

At S440, a related block of the sub-block in a reference image of thecurrent image block is determined according to the reference motionvector.

The reference image of the current image block may be a collocated frameof the current image block.

At S450, candidate motion vectors to be added to a motion vectorcandidate list are determined according to the motion vectors of therelated blocks.

In the ATMVP technology, the size of the sub-block can be adaptively setat the frame level. The size of the sub-block is 4×4 by default. When acertain condition is met, the size of the sub-block is set to 8×8. Forexample, at the encoding end, when the current image block is encoded,the average block size of each sub-block in the CU is calculated whenthe last encoded image block in the same time-domain layer is encoded inATMVP mode. When the average block size is greater than a threshold, thesize of the sub-block of the current image block is set to 8×8,otherwise the default value of 4×4 is used. In another word, in theATMVP technology, when the current image block is encoded, informationabout the size of the sub-block of the previous encoded image block inthe same time-domain layer needs to be stored.

In some embodiments, the size of the sub-block of the current imageblock is fixed to be greater than or equal to 64 pixels. There is noneed to store information about the size of the sub-block of the lastencoded image block, therefore, the storage space can be saved.

In some embodiments, the size of the sub-block and/or the size of therelated block of the sub-block are both fixed at 8×8 pixels.

In the ATMVP technology, the size of the sub-block can be adaptively setat the frame level. The size of the sub-block is 4×4 by default. When acertain condition is met, the size of the sub-block is set to 8×8. Forexample, at the encoding end, when the current image block is encoded,the average block size of each sub-block in the CU is calculated whenthe last encoded image block in the same time-domain layer is encoded inATMVP mode. When the average block size is greater than a threshold, thesize of the sub-block of the current image block is set to 8×8,otherwise the default value of 4×4 is used. At present, in a newgeneration of the versatile video coding standard (VVC), the motionvector is stored with a size of 8×8. When the size of the sub-block isset to 4×4, the size of the motion vector of the sub-block (also 4×4)does not meet the storage granularity of the motion vector in thecurrent standard. In addition, in the ATMVP technology, when the currentimage block is encoded, information about the size of the sub-block ofthe previous encoded image block in the same time-domain layer needs tobe stored.

In the embodiments of the present disclosure, the size of the sub-blockof the current image block can be set to 8×8 to adapt to the storagegranularity of the motion vector specified in the video standard VVC onthe one hand, and on the other hand, there is no need to store theinformation of the size of the sub-block of the last encoded imageblock, therefore, the storage space is saved.

On the premise that the size of the sub-block and/or the related blockof the sub-block is fixed to be equal to 64 pixels, the size of thesub-block and/or the related block of the sub-block may also be otherdimensions, for example, the size of the sub-block and/or the size ofthe related block of the sub-block is A×B, where A≤64, B≤64, and A and Bare both multiples of 4. For example, the size of the sub-block and/orthe size of the related block of the sub-block is 4× 16 pixels, or 16×4pixels.

In some embodiments, at S420, the at least some of the candidate motionvectors are sequentially scanned. When a first candidate motion vectorthat meets the preset condition is scanned, the scanning is stopped, andthe reference motion vector is determined according to the first scannedcandidate motion vector that meets the preset condition.

Determining the reference motion vector according to the first scannedcandidate motion vector that meets the preset condition may includeusing the first candidate motion vector that meets the preset conditionas a target neighboring block.

In some embodiments, the preset condition includes that the referenceimage of the candidate motion vector is the same as the reference imageof the current image block.

In some embodiments, at S450, when the motion vector of the relatedblock points to a specific reference image, or when the reference imageof the current image block is a specific reference image, the candidatemotion vectors to be added to the motion vector candidate list aredetermined according to the processed motion vector of the relatedblock. The processed motion vector of the related block is the same asthe motion vector of the related block before processing.

For example, the processed motion vector of the related block includes amotion vector obtained by scaling the motion vector of the related blockaccording to a scaling factor of 1, or a motion vector of the relatedblock skipping the scaling process.

In some embodiments, at S450, when the motion vector of the relatedblock points to a specific reference image, or when the reference imageof the current image block is a specific reference image, the candidatemotion vector to be added to the motion vector candidate list isdetermined without referencing to the motion vector of the relatedblock.

In the embodiment as shown in FIG. 4, diving the current image blockinto multiple sub-blocks with a size of 8×8 can adapt to the storagegranularity of the motion vector specified in the video standard VVC onthe one hand, and on the other hand, there is no need to store theinformation of the size of the sub-block of the last encoded imageblock, therefore, the storage space is saved.

The methods provided according to the embodiments of the presentdisclosure are described above with reference to FIGS. 1 and 4, anddevices corresponding to the above methods are described below. Thedescription of the devices and the description of the methods correspondto each other. Therefore, for content that is not described in detail,reference can be made to the foregoing description, which is notrepeated here.

FIG. 5 is a schematic block diagram of a device 500 for processing videoimages according to an embodiment of the present disclosure. The device500 can be used to execute, e.g., the method embodiment shown in FIG. 1.The device 500 includes an obtaining unit 510 configured to obtain Mcandidate motion vectors for adding to a motion vector candidate list ofa current image block, and a determination unit 520 configured tosequentially scan the N candidate motion vectors among the M candidatemotion vectors and determine a reference motion vector according to ascan result, where N is smaller than M.

The determination unit 520 is further configured to continue todetermine candidate motion vectors to be added to the motion vectorcandidate list according to the reference motion vector, the currentimage block, and a reference image of the current image block.

The determination unit 520 is also configured to determine a motionvector of the current image block according to the motion vectorcandidate list.

In the first step of the ATMVP technology, a time-domain vector of thecurrent image block is obtained by scanning all candidate motion vectorsthat are currently added in the motion vector candidate list. Forexample, the motion vector candidate list is usually filled with 4candidate motion vectors, and all the 4 candidate motion vectors mayneed to be scanned to obtain the time-domain vector of the current imageblock.

In the embodiments of the present disclosure, in the process ofobtaining the reference motion vector of the current image block, only N(N is smaller than M) candidate motion vectors among the M candidatemotion vectors that have been obtained are sequentially scanned.Comparing with the existing technology, the number of scans of thecandidate motion vectors in the process of obtaining the referencemotion vector of the current image block can be reduced. Applying thesolution provided by the present disclosure to the first step of theATMVP technology can simplify the redundant operations.

An official test sequence of the latest reference software VTM-2.0 ofversatile video coding is selected as the test sequence. The testconfiguration is RA configuration and LDB configuration. The solutionprovided by this disclosure is tested and the test result shows that theperformance gain of ATMVP technology can still be maintained after thenumber of scans is reduced.

Therefore, the solution provided in this disclosure can reduce thecomplexity of the ATMVP technology while maintaining the performancegain of the ATMVP technology.

In some embodiments, the obtaining unit 510 is configured to obtain Mcandidate motion vectors for adding to the motion vector candidate listof the current image block according to the motion vectors of Mneighboring blocks of the current image block in the current frame.

In some embodiments, the neighboring block is an image block that isadjacent to or has a certain distance to the current image block and ison the current frame.

In some embodiments, the determination unit 520 is configured tosequentially scan the first N candidate motion vectors among the Mcandidate motion vectors.

In some embodiments, M is equal to 4, and N is smaller than 4.

In some embodiments, N is equal to 1 or 2.

In some embodiments, the determination unit 520 is configured tosequentially scan N candidate motion vectors among the M candidatemotion vectors based on a preset condition and determine the referencemotion vector according to the scan result.

In some embodiments, the preset condition includes that the referenceframe pointed to by the candidate motion vector is the same as thereference image of the current image block.

In some embodiments, the determination unit 520 is configured tosequentially scan the N candidate motion vectors. When the firstcandidate motion vector that meets the preset condition is determined,the scanning is stopped, and according to the first scanned candidatemotion vector that meets the preset condition, the reference motionvector is determined.

In some embodiments, the determination unit 520 is configured to scale aspecific candidate motion vector in the motion vector candidate listwhen no candidate motion vector that meets the preset condition is foundamong the N candidate motion vectors, and determine the reference motionvector according to the scaled specific candidate motion vector.

In some embodiments, the specific candidate motion vector is the firstmotion vector or the last motion vector obtained in the scanning orderamong the N candidate motion vectors.

In some embodiments, the determination unit 520 is configured to scalethe specific candidate motion vector in the motion vector candidate listto make the reference frame pointed to by the scaled specific candidatemotion vector the same as the reference image of the current imageblock, and use the scaled specific candidate motion vector as thereference motion vector.

In some embodiments, the determination unit 520 is configured to use adefault value as the reference motion vector when no candidate motionvector that meets the preset condition is found among the N candidatemotion vectors.

In some embodiments, the default value is a motion vector of (0, 0).

In some embodiments, the determination unit 520 is configured to dividethe current image block into a plurality of sub-blocks, determine arelated block of the sub-block in the reference image of the currentimage block according to the reference motion vector, and determine acandidate motion vector to be added to the motion vector candidate listaccording to the motion vector of the related block.

In some embodiments, the size of the sub-block and/or the size of therelated block of the sub-block is fixed to be greater than or equal to64 pixels.

In some embodiments, the current image block is a coding unit CU.

In some embodiments, the determination unit 520 is configured todetermine a related block of the current image block in the referenceimage of the current image block according to the reference motionvector, and determine the candidate motion vector to be added to themotion vector candidate list according to the motion vector of therelated block.

In some embodiments, the determination unit 520 is configured to, whenthe motion vector of the related block points to the specific referenceimage, or when the reference image of the current image block is thespecific reference image, determine the candidate motion vectors to beadded to the motion vector candidate list according to the processedmotion vector of the related block. The processed motion vector of therelated block is the same as the motion vector of the related blockbefore processing.

In some embodiments, the processed motion vector of the related blockincludes a motion vector obtained by scaling the motion vector of therelated block according to a scaling factor of 1, or a motion vector ofthe related block skipping the scaling process.

In some embodiments, the determination unit 520 is configured to, whenthe motion vector of the related block points to the specific referenceimage, or when the reference image of the current image block is thespecific reference image, determine the candidate motion vector to beadded to the motion vector candidate list without referencing to themotion vector of the related block.

In some embodiments, the determination unit 520 is configured to, whenthe specific candidate motion vector points to the specific referenceimage, or when the reference image of the current image block is thespecific reference image, determine the candidate motion vectors to beadded to the motion vector candidate list according to the processedspecific candidate motion vector. The processed specific candidatemotion vector is the same as the specific candidate motion vector beforeprocessing.

In some embodiments, the processed motion vector of the related blockincludes a motion vector obtained by scaling the motion vector of therelated block according to a scaling factor of 1, or a motion vector ofthe related block skipping the scaling process.

In some embodiments, the determination unit 520 is configured to, whenthe specific candidate motion vector points to the specific referenceimage, or when the reference image of the current image block is thespecific reference image, determine the candidate motion vector to beadded to the motion vector candidate list without referencing to thespecific candidate motion vector.

In some embodiments, the motion vector candidate list is a Mergecandidate list.

In some embodiments, the reference image of the current image block is acollocated frame of the current image block.

In some embodiments, the size of the sub-block and/or the size of therelated block of the sub-block are fixed at 8×8 pixels.

Both the obtaining unit 510 and the determination unit 520 in theembodiments may be implemented by a processor.

FIG. 6 shows a device 600 for processing video images according toanother embodiment of the disclosure. The device 600 can be used toexecute, e.g., the method embodiment shown in FIG. 4. The device 600includes an obtaining unit 610 configured to obtain M candidate motionvectors for adding to a motion vector candidate list of a current imageblock, a determination unit 620 configured to sequentially scan at leastsome of the candidate motion vectors among the M candidate motionvectors and determine a reference motion vector according to the scanresult, and a division unit 630 configured to divide the current imageblock into multiple sub-blocks, where a size of the sub-block is fixedto be greater than or equal to 64 pixels.

The determination unit 620 is further configured to determine a relatedblock of the sub-block in a reference image of the current image blockaccording to the reference motion vector.

The determination unit 620 is further configured to determine candidatemotion vectors to be added to the motion vector candidate list accordingto the motion vector of the related block.

In the ATMVP technology, the size of the sub-block can be adaptively setat the frame level. The size of the sub-block is 4×4 by default. When acertain condition is met, the size of the sub-block is set to 8×8. Forexample, at the encoding end, when the current image block is encoded,the average block size of each sub-block in the CU is calculated whenthe last encoded image block in the same time-domain layer is encoded inATMVP mode. When the average block size is greater than a threshold, thesize of the sub-block of the current image block is set to 8×8,otherwise the default value of 4×4 is used. In another word, in theATMVP technology, when the current image block is encoded, informationabout the size of the sub-block of the previous encoded image block inthe same time-domain layer needs to be stored.

In some embodiments, the size of the sub-block of the current imageblock is fixed to be greater than or equal to 64 pixels. There is noneed to store information about the size of the sub-block of the lastencoded image block, therefore, the storage space can be saved.

In some embodiments, the size of the sub-block and/or the size of therelated block of the sub-block are both fixed at 8×8 pixels.

At present, in a new generation of the versatile video coding standard(VVC), the motion vector is stored with a size of 8×8. In theembodiments of the present disclosure, the size of the sub-block of thecurrent image block can be set to 8×8 to adapt to the storagegranularity of the motion vector specified in the video standard VVC onthe one hand, and on the other hand, there is no need to store theinformation of the size of the sub-block of the last encoded imageblock, therefore, the storage space is saved.

In some embodiments, the determination unit 620 is configured tosequentially scan the at least some of the candidate motion vectors.When the first candidate motion vector that meets a preset condition isscanned, the scanning is stopped, and according to the first scannedcandidate motion vector that meets the preset condition, the referencemotion vector is determined.

In some embodiments, the determination unit 620 is configured to use thefirst candidate motion vector that meets the preset condition as atarget neighboring block.

In some embodiments, the preset condition includes that a referenceimage of the candidate motion vector is the same as the reference imageof the current image block.

The obtaining unit 610, the determination unit 620, and the divisionunit 630 in the embodiments may be implemented by one or moreprocessors.

As described above, a motion vector of an image block may includeinformation of an image pointed to by the motion vector and adisplacement. In some application scenarios, the motion vector of animage block only includes the information of “displacement.” The imageblock additionally provides index information for indicating thereference image of the image block. For the encoded/decoded image block,the motion vector means the displacement of the reference block of theencoded/decoded image block on the reference image relative to the imageblock that has the same location as the encoded/decoded image block andis located in the reference image. When determining the reference blockof the encoded/decoded image block, the index information of thereference image of the encoded/decoded image block and the motion vectorof the encoded/decoded image block are needed to determine the referenceblock of the encoded/decoded image block. In the following, for the newdefinition of the motion vector (that is, it contains the “displacement”information but not the “image pointed to”), a video image processingmethod is provided.

FIG. 7 shows a method for processing video images according to anembodiment of the present disclosure.

At S710, M neighboring blocks of a current image block are determined.

The current image block is an image block to be encoded (or decoded).For example, the current image block is a coding unit (CU).

An image frame where the current image block is located is referred toas a current frame.

The neighboring block is an image block adjacent to or having a certaindistance to the current image block in a current image.

M neighboring blocks are image blocks in the current frame that havebeen encoded (or decoded).

For example, as shown in FIG. 2, the 4 neighboring blocks of the currentimage block are determined in an order of the image blocks shown in FIG.2 located at four locations A₁ (left)→B₁ (top)→B₀ (upper right)→A₀(lower left) around the current image block.

At S720, the N neighboring blocks among the M neighboring blocks arescanned sequentially, and a target neighboring block is determinedaccording to a scan result, where N is smaller than M.

Determining the target neighboring block according to the scan result ofthe N neighboring blocks may be determining the N neighboring blockssequentially based on a preset condition and determining the targetneighboring block according to the determination result.

For example, the preset condition is that a reference image of theneighboring block is the same as a reference image of the current imageblock.

The reference image of the current image block is a reference image witha shortest temporal distance to the image where the current image blockis located, or the reference image of the current image block is areference image preset at the encoding and decoding ends, or thereference image of the current image block is a reference imagespecified in a video parameter set, a sequence header, a sequenceparameter set, an image header, an image parameter set, or a sliceheader.

For example, the reference image of the current image block is acollocated frame of the current image block, and the collocated frame isa frame set in a slice-level information header for obtaining motioninformation for prediction.

According to the evolution of future technology, the preset conditionmay be given other different definitions, and the corresponding solutionalso falls within the scope of the present disclosure.

The process of determining the target neighboring blocks according tothe scan result of N neighboring blocks is described in detail below.

At S720, only N neighboring blocks out of the M neighboring blocksobtained in the process of S710 are scanned, which can reduce the numberof scans.

In some embodiments, at S720, the first N neighboring blocks among the Mneighboring blocks may be sequentially scanned.

When the M neighboring blocks of the current image block aresequentially determined in a preset order in the process of S710, thefirst N neighboring blocks obtained in the process of S720 refer to theN neighboring blocks determined first in the preset order.

In some embodiments, at S720, the last N neighboring blocks among the Mneighboring blocks may be sequentially scanned, or, the middle Nneighboring blocks among the M neighboring blocks may be sequentiallyscanned, which is not limited in the disclosure.

At S730, a related block of the current image block is determinedaccording to the motion vector of the target neighboring block, thecurrent image block, and the reference image of the current image block.

At S740, the current image block is encoded/decoded according to themotion vector of the related block.

In some embodiments, at S740, the reference block of the current imageblock is determined according to the motion vector of the related blockand the reference image.

For example, at S740, a candidate block list of the current image blockis constructed and the candidate blocks in the candidate block listinclude the M neighboring blocks and the related blocks. The currentimage block is encoded/decoded according to the reference block of thecandidate block in the candidate block list.

In one example, the candidate block list is a Merge candidate list ofthe current image block. In another example, the candidate block list isan AMVP candidate list of the current image block.

At the encoding end, an index of the candidate block of the currentblock is written into the bitstream. At the decoding end, after theindex is obtained, a candidate block corresponding to the index is foundfrom the candidate block list, and the reference block of the currentimage block is determined according to the reference block of thecandidate block, or the motion vector of the current image block isdetermined according to the motion vector of the candidate block.

For example, the reference block of the candidate block is directlydetermined as the reference block of the current image block, or themotion vector of the candidate block is directly determined as themotion vector of the current image block. For another example, at theencoding end, the MVD of the current block is also written into thebitstream. After the MVD is obtained at the decoding end, MVD is addedto the motion vector of the candidate block and the result is used asthe motion vector of the current block, and then the reference block ofthe current block is determined according to the motion vector and thereference image of the current block.

In the embodiments of the present disclosure, in the process ofobtaining the target neighboring block of the current image block, onlyN (N is smaller than M) neighboring blocks among the M neighboringblocks that have been obtained are sequentially scanned. Comparing withthe existing technology, the number of scans of the candidateneighboring blocks in the process of obtaining the target neighboringblocks of the current image block can be reduced, thereby reducingcomplexity.

In some embodiments, at S710, the four neighboring blocks of the currentimage block in the current frame are determined, that is, M is equal to4. At S720, N neighboring blocks among the 4 neighboring blocks arescanned, and N is smaller than 4.

For example, N is equal to 1. At S720, only the first neighboring blockamong the four neighboring blocks is scanned.

For another example, N is equal to 2 or 3.

The method of determining the target neighboring block according to thescan results of the N neighboring blocks at S720 is described below.

In some embodiments, at S720, the N neighboring blocks are sequentiallyscanned. When a first neighboring block that meets the preset conditionis found, the scanning is stopped, and the target neighboring block isdetermined according to the first scanned neighboring block that meetsthe preset condition.

For example, the preset condition is that the reference image of theneighboring block is the same as the reference image of the currentimage block.

According to the evolution of future technology, the preset conditionsmay also be given other definitions.

Hereinafter, the preset condition is that the reference image of theneighboring block is the same as the reference image of the currentimage block. Examples with this definition are described as follows.

For example, the first neighboring block that meets the preset conditionis used as the target neighboring block.

In some embodiments, at S720, when no neighboring block that meets thepreset condition is found among the N neighboring blocks, the methodfurther includes scaling the motion vector of a specific neighboringblock among the M neighboring blocks, and encoding/decoding the currentimage block according to a scaled motion vector.

For example, the reference block of the current image block isdetermined according to the scaled motion vector and the reference imageof the current image block.

In some embodiments, the specific neighboring block is the firstneighboring block, or the last neighboring block obtained according to ascanning order among the N neighboring blocks.

The specific neighboring block may also be a neighboring block obtainedin another scanning order among the N neighboring blocks.

In some embodiments, encoding/decoding the current image block accordingto the scaled motion vector includes scaling the motion vector of thespecific neighboring block to make the reference frame pointed to by thescaled motion vector the same as the reference image of the currentimage block, and using the image block pointed to by the scaled motionvector in the reference image of the current image block as thereference block of the current image block.

In some embodiments, at S720, when no neighboring block meeting thepreset condition is found among the N neighboring blocks, a defaultblock is used as the candidate reference block of the current imageblock.

For example, the default block is an image block pointed to by a motionvector (0, 0).

The process of determining the related block of the current image blockaccording to the motion vector of the target neighboring block, thecurrent image block, and the reference image of the current image blockat S730 is described below.

In some embodiments, determining the related block of the current imageblock according to the motion vector of the target neighboring block,the current image block, and the reference image of the current imageblock includes dividing the current image block into multiplesub-blocks, determining the related block of the sub-block in thereference image of the current image block according to the motionvector of the target neighboring block. The related block of the currentimage block includes the related block of the sub-block.

The related block may be referred to as a collocated block or acorresponding block.

For example, the current image block is a CU, and the sub-block obtainedafter dividing the CU may be referred to as a sub-CU.

In some embodiments, the size of the sub-block and/or the size of therelated block of the sub-block is fixed to be greater than or equal to64 pixels.

In some embodiments, the size of the sub-block and/or the size of therelated block of the sub-block are both fixed at 8×8 pixels.

In the ATMVP technology, the size of the sub-block can be adaptively setat the frame level. The size of the sub-block is 4×4 by default. When acertain condition is met, the size of the sub-block is set to 8×8. Forexample, at the encoding end, when the current image block is encoded,the average block size of each sub-block in the CU is calculated whenthe last encoded image block in the same time-domain layer is encoded inATMVP mode. When the average block size is greater than a threshold, thesize of the sub-block of the current image block is set to 8×8,otherwise the default value of 4×4 is used. At present, in a newgeneration of the versatile video coding standard (VVC), the motionvector is stored with a size of 8×8. When the size of the sub-block isset to 4×4, the size of the motion vector of the sub-block (also 4×4)does not meet the storage granularity of the motion vector in thecurrent standard. In addition, in the ATMVP technology, when encodingthe current image block, information about the size of the sub-block ofthe previous encoded image block in the same time-domain layer needs tobe stored.

In the embodiments of the present disclosure, the size of the sub-blockof the current image block can be set to 8×8 to adapt to the storagegranularity of the motion vector specified in the video standard VVC onthe one hand, and on the other hand, there is no need to store theinformation of the size of the sub-block of the last encoded imageblock, therefore, the storage space is saved.

On the premise that the size of the sub-block and/or the related blockof the sub-block is fixed to be equal to 64 pixels, the size of thesub-block and/or the related block of the sub-block may also be otherdimensions, for example, the size of the sub-block and/or the size ofthe related block of the sub-block is A×B, where A≤64, B≤64, and A and Bare both multiples of 4. For example, the size of the sub-block and/orthe size of the related block of the sub-block is 4×16 pixels, or 16×4pixels.

In some embodiments, determining the related block of the current imageblock according to the motion vector of the target neighboring block,the current image block, and the reference image of the current imageblock includes determining the related block of the current image blockin the reference image of the current image block according to themotion vector of the target neighboring block.

In some embodiments, at S740, when the reference image of the relatedblock is a specific reference image or when the reference image of thecurrent image block is a specific reference image, the candidatereference block of the current image block is determined according tothe processed motion vector of the related block and the reference imageof the current image block. The processed motion vector of the relatedblock is the same as the motion vector of the related block beforeprocessing.

For example, the processed motion vector of the related block includes amotion vector obtained by scaling the motion vector of the related blockaccording to a scaling factor of 1, or a motion vector of the relatedblock skipping the scaling process.

In some embodiments, at S740, when the reference image of the relatedblock is a specific reference image, or when the reference image of thecurrent block is a specific reference image, the candidate referenceblock of the current image block is determined without referencing tothe motion vector of the related block.

In some embodiments, at S740, when the motion vector of the specificneighboring block points to a specific reference image or when thereference image of the current image block is a specific referenceimage, the reference block of the current image block is determinedaccording to the processed motion vector of the related block and thereference image of the current image block. The processed motion vectorof the related block is the same as the motion vector of the relatedblock before processing.

The processed motion vector of the related block includes a motionvector obtained by scaling the motion vector of the related blockaccording to a scaling factor of 1, or a motion vector of the relatedblock skipping the scaling process.

In the embodiments of the present disclosure, in the process ofobtaining the target neighboring block of the current image block, onlyN (N is smaller than M) neighboring blocks among the M neighboringblocks that have been obtained are sequentially scanned. Comparing withthe existing technology, the number of scans of the candidateneighboring blocks in the process of obtaining the target neighboringblocks of the current image block can be reduced, thereby reducingcomplexity.

When no neighboring block whose reference frame is the same as thecollocated frame of the current frame is found among the N neighboringblocks, the motion vector of one neighboring block among the Nneighboring blocks is scaled to make the reference frame the same as thecollocated frame of the current frame, and then the scaled motion vectoris used as the motion vector of the current image block. In this way,the accuracy of the motion vector of the current image block can beimproved.

Diving the current image block into multiple sub-blocks with a size of8×8 can adapt to the storage granularity of the motion vector specifiedin the video standard VVC on the one hand, and on the other hand, thereis no need to store the information of the size of the sub-block of thelast encoded image block, therefore, the storage space is saved.

In some embodiments, the process of determining the motion vector of thecurrent image block involves using a motion vector of a certain imageblock on another image to determine the motion vector of the imageblock. For convenience of description, the image block is referred to asa first image block, and the certain image block on another image to beused is referred to as a time-domain reference block or a related blockof the first image block. The first image block and the time-domainreference block (or the related block) of the first image block arelocated on different images. Then, in the process of determining themotion vector of the first image block using the motion vector of thetime-domain reference block (or the related block), the motion vector ofthe time-domain reference block (or the related block) needs to bescaled. For convenience of description, the term “related block” is usedin the disclosure.

For example, when the ATMVP technology is applied in constructing anAMVP candidate list, after the related block of the current image blockis determined according to the ATMVP technology, and when the motionvector of the current image block is being determined according to themotion vector of the related block, the motion vector of the relatedblock needs to be scaled, and then motion vector of the current image isdetermined according to the scaled motion vector. Generally speaking, ascaling factor of the motion vector of the related block is determinedbased on a temporal distance between the reference image pointed to bythe motion vector of related block and the image where the related blockis located, and a temporal distance between the reference image of thecurrent image block and the image where the current image block islocated.

In one example, the motion vector of the related block is referred to asMV 2, and the index value of the reference frame of the reference imagepointed to by the motion vector MV 2 is x. The index value x of thereference frame is the difference between the sequence number of thereference image pointed to by MV 2 (for example, POC) and the sequencenumber of the image where the related block is located. The index valueof the reference frame of the reference image of the first image blockis y. The index value y of the reference frame is the difference betweenthe sequence number of the reference image of the first image block andthe sequence number of the image where the first image block is located.Then, the scaling factor of the motion vector MV 2 is y/x. In someembodiments, the product of the motion vector MV 2 and y/x may be usedas the motion vector of the first image block.

However, when the motion vector MV 2 of the related block points to aspecific reference image, or when the reference image of the first imageblock is a specific reference image, because the definition of thetemporal distance between the specific reference image and the imagewhere the first image block is located is not clear, it may bemeaningless to scale the motion vector MV 2 of the related block.

In some embodiments, when the motion vector of the current image blockis determined according to the motion vector of the related block, andwhen the motion vector of the related block points to a specificreference image, or when the reference image of the current image blockis a specific reference image, the motion vector of the current imageblock is determined according to the processed motion vector of therelated block. The processed motion vector of the related block is thesame as the motion vector of the related block before processing.

For example, the processed motion vector of the related block includes amotion vector obtained by scaling the motion vector of the related blockaccording to a scaling factor of 1, or a motion vector of the relatedblock skipping the scaling process.

In some embodiments, when the motion vector of the current image blockis determined according to the motion vector of the related block, andwhen the motion vector of the related block points to a specificreference image, or when the reference image of the current image blockis a specific reference image, the motion vector of the current imageblock is determined without referencing to the motion vector of therelated block.

FIG. 8 shows a method for processing video images according to anotherembodiment of the present disclosure.

At S810, M neighboring blocks of a current image block are determined.

The process of S810 may correspond to the process of S710 in the aboveembodiment.

At S820, at least some of the neighboring blocks among the M neighboringblocks are sequentially scanned, and a target neighboring block isdetermined according to a scan result.

In some embodiments, some of the neighboring blocks among the Mneighboring blocks are sequentially scanned, and the target neighboringblock is determined according to a scan result.

In some embodiments, all neighboring blocks among the M neighboringblocks are sequentially scanned, and the target neighboring block isdetermined according to a scan result.

At S830, the current image block is divided into multiple sub-blocks anda size of the sub-block is fixed to be greater than or equal to 64pixels.

At S840, a related block of the current image block in a reference imageof the current image block is determined according to a motion vector ofthe target neighboring block and the sub-block.

In some embodiments, the reference image of the current image block is areference image with a shortest temporal distance to the image where thecurrent image block is located.

In some embodiments, the reference image of the current image block is areference image preset at the encoding end.

In some embodiments, the reference image of the current image block is areference image specified in a video parameter set, a sequence header, asequence parameter set, an image header, an image parameter set, or aslice header.

At S850, the current image block is encoded/decoded according to themotion vector of the related block.

In the embodiments of the disclosure, the size of the sub-block of thecurrent image block is fixed to be greater than or equal to 64 pixels,and there is no need to store the information of the size of thesub-block of the previous encoded image block, therefore, storage spacecan be saved.

In some embodiments, the size of the sub-block and/or the size of thetime-domain reference block of the sub-block are both fixed at 8×8pixels.

At present, in a new generation of the versatile video coding standard(VVC), the motion vector is stored with a size of 8×8. In theembodiments of the present disclosure, the size of the sub-block of thecurrent image block can be set to 8×8 to adapt to the storagegranularity of the motion vector specified in the video standard VVC onthe one hand, and on the other hand, there is no need to store theinformation of the size of the sub-block of the last encoded imageblock, therefore, the storage space is saved.

On the premise that the size of the sub-block and/or the related blockof the sub-block is fixed to be equal to 64 pixels, the size of thesub-block and/or the related block of the sub-block may also be otherdimensions, for example, the size of the sub-block and/or the size ofthe related block of the sub-block is A×B, where A≤64, B≤64, and A and Bare both multiples of 4. For example, the size of the sub-block and/orthe size of the related block of the sub-block is 4×16 pixels, or 16×4pixels.

In some embodiments, at step S820, at least some of the neighboringblocks are sequentially scanned. When a first neighboring block thatmeets a preset condition is scanned, the scanning is stopped, andaccording to the first scanned neighboring block that meets the presetcondition, a target neighboring block is determined.

For example, the first neighboring block that meets the preset conditionis used as the target neighboring block.

For example, the preset condition is that the reference image of theneighboring block is the same as the reference image of the currentimage block.

In some embodiments, at S840, a related block of the sub-block in thereference image of the current image block is determined according tothe motion vector of the target neighboring block and the sub-block. Therelated block of the current image block includes the related block ofthe sub-block.

The methods provided according to the embodiments of the presentdisclosure are described above with reference to FIGS. 7 and 8, anddevices corresponding to the above methods are described below. Thedescription of the devices and the description of the methods correspondto each other. Therefore, for content that is not described in detail,reference can be made to the foregoing description, which is notrepeated here.

FIG. 9 is a schematic block diagram of a device 900 for processing videoimages according to an embodiment of the present disclosure. The device900 can be used to execute, e.g., the method embodiment shown in FIG. 7.The device 900 includes an obtaining unit 910 configured to obtain Mneighboring blocks of a current image block, a determination unit 920configured to sequentially scan the N neighboring blocks among the Mneighboring blocks and determine a target neighboring block according toa scan result, where N is smaller than M, and an encoding/decoding unit930 configured to encode/decode the current image block according to themotion vector of a related block of the current image block, which isdetermined by the determination unit 920 according to a motion vector ofthe target neighboring block, the current image block, and a referenceimage of the current image block.

In the embodiments of the present disclosure, in the process ofobtaining the target neighboring block of the current image block, onlyN (N is smaller than M) neighboring blocks among the M neighboringblocks that have been obtained are sequentially scanned. Comparing withthe existing technology, the number of scans of the candidateneighboring blocks in the process of obtaining the target neighboringblocks of the current image block can be reduced, thereby reducingcomplexity.

In some embodiments, M is equal to 4, and N is smaller than 4.

In some embodiments, N is equal to 1 or 2.

In some embodiments, the determination unit 920 is configured tosequentially scan the first N neighboring blocks among the M neighboringblocks.

In some embodiments, the obtaining unit 910 is configured to obtain Mneighboring blocks of the current image block sequentially in a presetorder. The first N neighboring blocks refer to the N neighboring blocksdetermined first in the preset order.

In some embodiments, the determination unit 920 is configured tosequentially scan the N neighboring blocks. When a first neighboringblock that meets a preset condition is scanned, the scanning is stopped,and a target neighboring block is determined according to the scannedfirst neighboring block that meets the preset condition.

In some embodiments, the determination unit 920 is configured to use thefirst neighboring block that meets the preset condition as the targetneighboring block.

In some embodiments, the preset condition includes that the referenceimage of the neighboring block is the same as the reference image of thecurrent image block.

In some embodiments, the encoding/decoding unit 930 is configured todetermine a reference block of the current image block according to amotion vector of the related block and a reference image.

In some embodiments, the encoding/decoding unit 930 is configured toconstruct a candidate block list of the current image block. Thecandidate blocks in the candidate block list include the M neighboringblocks and the related blocks. According to the reference blocks of thecandidate blocks in the candidate block list, the current image block isencoded and decoded.

In some embodiments, the encoding/decoding unit 930 is furtherconfigured to, when no neighboring block that meets the preset conditionis found among the N neighboring blocks, scale a motion vector of aspecific neighboring block among the M neighboring blocks, andencode/decode the current image block according to the scaled motionvector.

In some embodiments, the encoding/decoding unit 930 is configured todetermine the reference block of the current image block according tothe scaled motion vector and the reference image of the current imageblock.

In some embodiments, the specific neighboring block is a firstneighboring block, or a last neighboring block obtained in a scanningorder among the N neighboring blocks.

In some embodiments, the encoding/decoding unit 930 is configured toscale the motion vector of the specific neighboring block to make areference frame pointed to by the scale motion vector the same as thereference image of the current image block, and use the image blockpointed to by the scaled motion vector in the reference image of thecurrent image block as the reference block of the current image block.

In some embodiments, the determination unit 920 is configured to use adefault block as the reference block of the current image block when noneighboring block that meets the preset condition is found among the Nneighboring blocks.

In some embodiments, the default block is an image block pointed to by amotion vector (0, 0).

In some embodiments, the determination unit 920 is configured to dividethe current image block into a plurality of sub-blocks, determine arelated block of the sub-block in the reference image of the currentimage block according to the motion vector of the target neighboringblock. The related block of the current image block includes the relatedblock of the sub-block.

In some embodiments, the size of the sub-block and/or the size of therelated block of the sub-block is fixed to be greater than or equal to64 pixels.

In some embodiments, the current image block is a coding unit (CU).

In some embodiments, the determination unit 920 is configured todetermine a related block of the current image block in the referenceimage of the current image block according to the motion vector of thetarget neighboring block.

In some embodiments, the neighboring block is an image block adjacent toor having a certain distance to the current image block on the currentimage.

In some embodiments, the encoding/decoding unit 930 is configured to,when the reference image of the related block is the specific referenceimage, or when the reference image of the current image block is thespecific reference image, determine the reference block of the currentimage block according to the processed motion vector of the relatedblock and the reference image of the current image block.

The processed motion vector of the related block is the same as themotion vector of the related block before processing.

In some embodiments, the processed motion vector of the related blockincludes a motion vector obtained by scaling the motion vector of therelated block according to a scaling factor of 1, or a motion vector ofthe related block skipping the scaling process.

In some embodiments, the encoding/decoding unit 930 is configured to,when the reference image of the related block is the specific referenceimage, or when the reference image of the current block is the specificreference image, determine the reference block of the current imageblock without referencing to the motion vector of the related block.

In some embodiments, the determination unit 920 is configured to, whenthe motion vector of the specific neighboring block points to thespecific reference image or when the reference image of the currentimage block is the specific reference image, determine the referenceblock of the current image block according to the processed motionvector of the related block and the reference image of the current imageblock. The processed motion vector of the related block is the same asthe motion vector of the related block before processing.

In some embodiments, the processed motion vector of the related blockincludes a motion vector obtained by scaling the motion vector of therelated block according to a scaling factor of 1, or a motion vector ofthe related block skipping the scaling process.

The obtaining unit 910, the determination unit 920, and theencoding/decoding unit 930 in the embodiments may be implemented by oneor more processors.

FIG. 10 schematically shows a device 1000 for processing video imagesaccording to another embodiment of the present disclosure. The device1000 can be used to execute, e.g., the method embodiment shown in FIG.8. The device 1000 includes an obtaining unit 1010 configured to obtainM neighboring blocks of a current image block, a determination unit 1020configured to sequentially scan at least some of the neighboring blocksamong the M neighboring blocks and determine a target neighboring blockaccording to a scan result, a division unit 1030 configured to dividethe current image block into multiple sub-blocks, where a size of thesub-block is fixed to be greater than or equal to 64 pixels, and anencoding/decoding unit 1040 configured to encode/decode the currentimage block according to a motion vector of a related block of thecurrent image block, which is determined in a reference image of thecurrent image block by the determination unit 1020 according to themotion vector of the target neighboring block and sub-block.

In some embodiments, the size of the sub-block of the current imageblock is fixed to be greater than or equal to 64 pixels. There is noneed to store information about the size of the sub-block of the lastencoded image block, therefore, the storage space can be saved.

In some embodiments, the size of the sub-block and/or the size of thetime-domain reference block of the sub-block are both fixed at 8×8pixels.

At present, in a new generation of the versatile video coding standard(VVC), the motion vector is stored with a size of 8×8. In theembodiments of the present disclosure, the size of the sub-block of thecurrent image block can be set to 8×8 to adapt to the storagegranularity of the motion vector specified in the video standard VVC onthe one hand, and on the other hand, there is no need to store theinformation of the size of the sub-block of the last encoded imageblock, therefore, the storage space is saved.

On the premise that the size of the sub-block and/or the related blockof the sub-block is fixed to be equal to 64 pixels, the size of thesub-block and/or the related block of the sub-block may also be otherdimensions, for example, the size of the sub-block and/or the size ofthe related block of the sub-block is A×B, where A≤64, B≤64, and A and Bare both multiples of 4. For example, the size of the sub-block and/orthe size of the related block of the sub-block is 4×16 pixels, or 16×4pixels.

In some embodiments, sequentially scanning the at least some of theneighboring blocks among the M neighboring blocks and determining thetarget neighboring block according to the scan result includessequentially scanning the at least some of the neighboring blocks, whena first neighboring block that meets a preset condition is scanned,stopping the scanning, and determining the target neighboring blockaccording to the first scanned neighboring block that meets the presetcondition.

In some embodiments, the determination unit 1020 is configured to usethe first neighboring block that meets the preset condition as a targetneighboring block.

In some embodiments, the preset condition includes that a referenceimage of the neighboring block is the same as the reference image of thecurrent image block.

In some embodiments, the determination unit 1020 is configured todetermine a related block of the sub-block in the reference image of thecurrent image block according to the motion vector of the targetneighboring block and the sub-block. The related block of the currentimage block includes the related block of the sub-block.

The obtaining unit 1010, the determination unit 1020, the division unit1030, and the encoding/decoding unit 1040 in the embodiments may beimplemented by one or more processors.

FIG. 11 schematically shows a device 1100 for processing video imagesaccording to another embodiment of the present disclosure. The device1100 may be used to execute the method embodiments described above. Thedevice 1100 includes a processor 1110 and a memory 1120. The memory 1120is used to store instructions. The processor 1110 is configured toexecute the instructions stored in the memory 1120 to perform a methodconsistent with the disclosure, such as one of the above-describedexample methods.

In some embodiments, as shown in FIG. 11, the device 1100 furtherincludes a communication interface 1130 for communicating with externaldevices. For example, the processor 1110 is configured to control thecommunication interface 1130 to receive and/or send signals.

The devices 500, 600, 900, 1000, and 1100 provided in this disclosuremay be applied to an encoder or a decoder.

A computer storage medium is further provided according to an embodimentof the present disclosure to store computer programs. When the computerprogram is executed by a computer, a method provided in the foregoingembodiments is performed.

An embodiment of the present disclosure further provides a computerprogram product containing instructions, which are executed by acomputer to perform a method provided by the foregoing embodiments.

In the above embodiments, it can be implemented in whole or in part bysoftware, hardware, firmware, or any combination thereof. Whenimplemented using software, it can be implemented in whole or in part inthe form of a computer program product. The computer program productincludes one or more computer instructions. When computer instructionsare loaded and executed on a computer, the processes or functionsaccording to the embodiments of the present disclosure are generated inwhole or in part. The computer may be a general-purpose computer, aspecial-purpose computer, a computer network, or other programmabledevices. Computer instructions can be stored in a computer-readablestorage medium or transmitted from one computer-readable storage mediumto another computer-readable storage medium. For example, the computerinstructions can be transmitted from a website, computer, server, ordata center via a wired (e.g., coaxial cable, optical fiber, digitalsubscriber line (DSL)) or wireless (such as infrared, wireless,microwave, etc.) manner to another website, computer, server or datacenter. The computer-readable storage medium may be any available mediumthat can be accessed by a computer or a data storage device includingone or more available medium integrated servers, data centers, and thelike. The usable media can be magnetic media (such as floppy disks, harddisks and magnetic tapes), optical media (such as high-density digitalvideo disks (DVD)), or semiconductor media (such as solid-state disks(SSD)).

Those of ordinary skills in the art may realize that the units andalgorithms described in the embodiments of the disclosure can beimplemented by electronic hardware, or a combination of computersoftware and electronic hardware. Whether these functions are executedin hardware or software depends on the specific application of thetechnical solution and design constraints. Professional technicians canuse different methods to implement the described functions for eachspecific application, but such implementation should not be consideredbeyond the scope of this disclosure.

In the embodiments provided in this disclosure, the disclosed system,device, and method may be implemented in other ways. For example, thedevice embodiments described above are only schematic. For example, thedivision of the units is only a division of logical functions. In actualimplementation, there may be other divisions, for example, multipleunits or components may be combined or integrated into another system,or some features may be ignored or not implemented. In addition, thedisplayed or discussed mutual coupling or direct coupling orcommunication connection may be indirect coupling or communicationconnection through some interfaces, devices or units, and may be inelectrical, mechanical or other forms.

The units described as separate components may or may not be physicallyseparated, and the components displayed as units may or may not bephysical units, that is, they may be located in one place or may bedistributed on multiple network units. Some or all of the units may beselected according to actual needs to achieve the purpose of thesolution of this embodiment.

In addition, each functional unit in each embodiment of the presentdisclosure may be integrated into one processing unit, or each unit mayexist alone physically, or two or more units are integrated into oneunit.

The above is only the specific implementations of this disclosure, butthe scope of this disclosure is not limited to this. Any person skilledin the art can easily think of changes or replacements within thetechnical scope disclosed in this disclosure, which should be covered bythe scope of this disclosure. Therefore, the scope of the inventionshall be subject to the claims.

1. A video processing method comprising: in response to a size of acoding unit being not smaller than 8×8, performing processing including:dividing the coding unit into several sub-blocks each having a fixedsize of 8×8; scanning a left neighboring block of the coding unit and:in response to a reference frame pointed to by a motion vector of theleft neighboring block being same as a co-located reference image of thecoding unit, determining the motion vector of the left neighboring blockas a reference motion vector of the coding unit; and in response to thereference frame pointed to by the motion vector of the left neighboringblock being different from the co-located reference image of the codingunit, determining a default value (0, 0) as the reference motion vectorof the coding unit; determining a related reference block of one of thesub-blocks of the coding unit in the co-located reference image of thecoding unit according to the reference motion vector of the coding unit;in response to a motion vector of the related reference block of the oneof the sub-blocks pointing to a short-term reference image: determininga scaling factor of the motion vector of the related reference block ofthe one of the sub-blocks according to: a temporal distance between areference image pointed to by the motion vector of the related referenceblock of the one of the sub-blocks and the co-located reference image ofthe coding unit, and a temporal distance between the co-locatedreference image of the coding unit and an image containing the codingunit; scaling the motion vector of the related reference block of theone of the sub-blocks using the scaling factor; and determining motioninformation of the one of the sub-blocks according to the motion vectorafter being scaled; in response to the motion vector of the relatedreference block of the one of the sub-blocks pointing to a long-termreference image: setting the scaling factor of the motion vector of therelated reference block of the one of the sub-blocks to 1; scaling themotion vector of the related reference block of the one of thesub-blocks using the scaling factor; and determining the motioninformation of the one of the sub-blocks according to the motion vectorafter being scaled; and performing prediction for the coding unitaccording to the motion information of the one of the sub-blocks; and inresponse to the size of the coding unit being smaller than 8×8, skippingthe processing.
 2. A video processing device comprising: a memorystoring computer executable instructions; and a processor configured toexecute the instructions to: in response to a size of a coding unitbeing not smaller than 8×8, perform processing including: dividing thecoding unit into several sub-blocks each having a fixed size of 8×8;scanning a left neighboring block of the coding unit and: in response toa reference frame pointed to by a motion vector of the left neighboringblock being same as a co-located reference image of the coding unit,determining the motion vector of the left neighboring block as areference motion vector of the coding unit; and in response to thereference frame pointed to by the motion vector of the left neighboringblock being different from the co-located reference image of the codingunit, determining a default value (0, 0) as the reference motion vectorof the coding unit; determining a related reference block of one of thesub-blocks of the coding unit in the co-located reference image of thecoding unit according to the reference motion vector of the coding unit;in response to a motion vector of the related reference block of the oneof the sub-blocks pointing to a short-term reference image: determininga scaling factor of the motion vector of the related reference block ofthe one of the sub-blocks according to:  a temporal distance between areference image pointed to by the motion vector of the related referenceblock of the one of the sub-blocks and the co-located reference image ofthe coding unit, and  a temporal distance between the co-locatedreference image of the coding unit and an image containing the codingunit; scaling the motion vector of the related reference block of theone of the sub-blocks using the scaling factor; and determining motioninformation of the one of the sub-blocks according to the motion vectorafter being scaled; in response to the motion vector of the relatedreference block of the one of the sub-blocks pointing to a long-termreference image: setting the scaling factor of the motion vector of therelated reference block of the one of the sub-blocks to 1; scaling themotion vector of the related reference block of the one of thesub-blocks using the scaling factor; and determining the motioninformation of the one of the sub-blocks according to the motion vectorafter being scaled; and performing prediction for the coding unitaccording to the motion information of the one of the sub-blocks; and inresponse to the size of the coding unit being smaller than 8×8, skip theprocessing.